1. Field of the Invention
This invention relates to paper-handling machinery, and specifically, to devices for mounting, assembling and disassembling rotating roller elements.
2. Discussion of the Prior Art
Workers in the art are familiar with the conventional constructions used for high speed paper-handling machinery, such as printers, page handlers, collators, sorting machinery and the like. A very typical construction involves a number of driven cylindrical rollers or drums, the circumferences of which are furnished with a rubber or other, like frictional material surface which drive the paper item by friction and form a "track" or path down which the paper is driven.
Paper itself is an abrasive and deleterious material, and the inks and coatings often found on paper products contain chemicals, abrasives and other materials. These characteristics tend to limit the useful life of the frictional coatings upon drive rollers, with the result that provision must be made for the frictional material to be replaced from time to time with fresh material. As an example, a conventional small check-sorting device such as the Unisys SNDP product will typically require that the friction drive material on drive rollers be replaced after 250,000 documents have been driven if feeding and transport performance are to be maintained. In normal operation, this attention would be required approximately every ninety (90) days.
Typically, in large and costly machinery, such replacement function is a task assigned to skilled service personnel and involves a certain degree of disassembly and inspection. Replacement processes are conventionally designed to be performed by trained personnel who have suitable tools and equipment available, and for this reason, rollers are typically mounted by means and methods which require tools for disassembly--screws, retaining rings and the like. In fact, it is sometimes considered advantageous to make roller disassembly difficult or impossible without the use of special tools, as tending to eliminate unauthorized disassembly by unskilled personnel.
With the present trend to smaller and simpler paper handling machinery, especially in the banking and financial services markets, we find an accompanying trend away from the concept of routine service by skilled personnel, and a trend instead towards having routine service performed by unskilled users--the clerks and tellers who typically use these machines on a day-to-day basis. As paper-handling machines become smaller and less expensive, the costs of service by trained personnel become proportionally much higher when seen as part of the "lifetime cost" of owning and operating the machine. Accordingly, the customers for these machines are demanding that routine service attentions to the machines, such as the replacement of friction rollers, be made within the capacity of unskilled operators to perform reliably and without oversight.